/*
OpenMVL Matrix Vector Library
Copyright (c) 2009 FluidInteractive (R)
 
This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising
from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:
 
1. The origin of this software must not be misrepresented; you must
not claim that you wrote the original software. If you use this
software in a product, an acknowledgment in the product documentation
would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must
not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
 
Written by: Nicola Candussi <nicola@fluidinteractive.com>
*/

//expr_unary.h

#ifndef MVL_EXPR_UNARY_HPP
#define MVL_EXPR_UNARY_HPP

#include "expr.hpp"
#include "element_unary.hpp"

namespace mvl {

template<typename E, typename F>
class expr_unary : public expr< expr_unary<E, F> > 
{ 
public:
    typedef expr_unary self_t;

    typedef E expr_t;
    typedef typename expr_t::const_closure_t expr_closure_t; 

private:
    typedef F functor_t;

public:
    typedef typename functor_t::layout_t    layout_t;
    typedef typename functor_t::value_type  value_type;
    typedef typename layout_t::order        order;
    typedef typename layout_t::Rows         Rows;
    typedef typename layout_t::Cols         Cols;
    typedef typename layout_t::Size         Size;

    typedef const self_t const_closure_t;
    typedef const_closure_t closure_t;

public:
    expr_unary(expr_t const& e) : m_e(e) { };

   // using expr<self_t>::operator();

    //access
    template<typename Entry>
    value_type at() const {
        return functor_t::template at<Entry>(m_e);
    }

private:
    expr_closure_t m_e;
};

template<typename E>
struct operator_neg_traits
{
    typedef const expr_unary<
        E,
        element_unary<E, fn_neg, tagfn_neg>
    > type;
};

//operator -
template<typename E>
inline 
typename operator_neg_traits<E>::type
operator - (expr<E> const& e) {
    typedef typename operator_neg_traits<E>::type expr_t;
    return expr_t(e());
}


} // namespace mvl

#endif
